This invention deals with units for injecting different materials by a syringe and/or with use of manifolds and similar things and particularly during cardiac catheterization and related procedures. Commonly at the present time this is done by connecting a manifold which has a number of three-way stopcocks on it in order to direct one particular solution to a particular route. And commonly this consists of three three-way stopcocks which are arranged in a series to make the manifolds and then such a manifold is connected to the tip of a syringe. However in the experience of this inventor the use of three-day stopcocks is hard and problematic; it causes significant discomfort in some hands and fingers, even pain if it has to be done in a hurry and quickly without using time and care, which are hard to find in these times. Rotation of a three-day stopcock also needs significant work and full functioning hands which increases handling and is a kind of extra work that causes discomfort and tiredness. So a better alternative will make some users happier. This inventor therefore introduces units that have less numbers of buttons to be used and also allow a pressure button to be used instead of a three-day stopcock.